Impedance spectroscopy of nanostructured ZnO morphologies
Impedance spectroscopy of nanostructured ZnO morphologies
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DOI：
10.1557/s43578-021-00219-0
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发表时间：
2021-04
影响因子：
2.7
通讯作者：
Rusiri Rathnasekara;P. Hari
中科院分区：
文献类型：
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作者：
Rusiri Rathnasekara;P. Hari
在本研究中，我们在300℃、500℃和700℃的温度下制备了四种纳米结构的氧化锌：纳米带、纳米棒、纳米颗粒和纳米梭子，并用扫描电子显微镜、透射电子显微镜、X射线衍射谱和差示扫描量热仪对其结构进行了研究。用紫外-可见光谱和光致发光(PL)对其光学性质进行了分析。用Cole-Cole作图法和电阻率法研究了其电输运特性。从阻抗谱分析中提取了各形貌下的载流子寿命、RC时间常数以及晶界参数。我们观察到，总的来说，所有样品的电阻都随着温度的升高而降低，而纳米棒、纳米梭子和纳米带在更高的温度下由于晶界和晶界而显示出明确的半圆形轮廓。润湿性研究表明，纳米氧化锌颗粒的表面具有疏水性，而纳米棒、纳米带和纳米梭子则形成了超疏水表面。基于阻抗研究的最佳氧化锌纳米形态可用于开发染料敏化太阳能电池的电极。
In this study, four nanostructured ZnO morphologies, nanoribbons, nanorods, nanoparticles, and nanoshuttles, were synthesized at annealing temperatures of 300 °C, 500 °C, and 700 °C. Structural properties were studied by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Diffraction Spectroscopy (XRD), and Differential Scanning Calorimetry (DSC). Optical properties were analyzed by UV–Visible Spectroscopy and Photoluminescence (PL). Electrical transport properties were studied by the Cole–Cole plot technique and electrical resistivity. From the impedance spectroscopy analysis, we extracted the carrier lifetime, the RC time constant, and grain and grain boundary parameters in each morphology. We observed that resistance decreased with increasing temperature in all samples in general, while nanorods, nanoshuttles, and nanoribbons showed well-defined semicircle profiles due to grain and grain boundaries at higher temperatures. From wettability studies, we obtained that surface with ZnO nanoparticles has hydrophobic properties, while nanorods, nanoribbons, and nanoshuttles resulted in a superhydrophobic surface. The optimum ZnO nanomorphology based on impedance studies can be used for developing electrodes for dye-sensitized solar cells.